A purification system for fluorine-containing wastewater

Abstract

The invention discloses a purification system for fluorine-containing wastewater, which relates to the field of sewage treatment. The system comprises a power base and a reactor. A mixing mechanism for automatically adjusting the adsorption range of flocs in a reaction solution based on a rotation speed is installed in the inner cavity of the reactor. The mixing mechanism comprises a contraction-expansion mixing component and an adsorption carrier. The outer surface of the adsorption carrier is provided with a plurality of adsorption protrusions. A scraping mechanism is installed at the bottom of the inner cavity of the reactor. The invention dynamically controls the mixing rotation speed by real-time monitoring of the floc content in the reaction solution. Once the floc content in the reaction solution exceeds a standard, the rotation speed is promptly increased to utilize the adsorption carrier to adsorb the flocs and bring them to a discharge cavity at the bottom, thereby ensuring that the floc content in the upper layer of the reaction solution is always within a normal range, not affecting the main reaction, effectively avoiding the problem of flocs wrapping reactants, promptly removing excess flocs, maintaining the activity of the reaction interface, and simultaneously maintaining a maximized reaction rate to remove fluoride ions.

Description

Technical Field

[0001] The present invention relates to the field of sewage treatment, in particular to a purification system for fluorine-containing wastewater. Background Art

[0002] Efficient treatment of fluoride-containing wastewater is one of the difficulties in industrial pollution control, especially in the electronics and metallurgical industries, where fluoride concentrations in wastewater can reach 200-1000 mg / L, far exceeding emission standards (≤10 mg / L). Traditional chemical precipitation methods generate calcium fluoride precipitates by adding calcium salts. However, the resulting flocs are small in size (<10μm) and have a loose structure, which easily forms colloidal suspended matter that is difficult to settle, resulting in low solid-liquid separation efficiency. In addition, excess flocs can encapsulate unreacted Ca 2+ and F - , inhibiting the reaction process, forcing the dosage of the reagent to increase by 30%-50%, significantly increasing the treatment cost;

[0003] Some existing technologies have proposed using multi-stage agitation to enhance flocculation, but fixed-speed agitators can easily cause shearing and fragmentation when there are excessive flocs, hindering their growth. Others have used magnetic carriers to adsorb flocs, but these carriers are difficult to recover and are easily covered by flocs and become ineffective. Other studies have attempted to add polymer coagulants (such as PAM), but this carries the risk of secondary contamination and has limited effectiveness in removing low-concentration fluoride. Summary of the Invention

[0004] The object of the present invention is to provide a purification system for fluorine-containing wastewater, which can dynamically regulate floc adsorption and removal, taking into account both reaction efficiency and operation stability, so as to solve the problems raised in the above background technology.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solution: a purification system for fluorine-containing wastewater, comprising a power base and a reactor, wherein a mixing mechanism is installed in the inner cavity of the reactor for automatically adjusting the floc adsorption range in the reaction solution based on the rotational speed, the mixing mechanism comprises a contraction-expansion mixing component and an adsorption carrier, the outer surface of the adsorption carrier is provided with a plurality of adsorption protrusions, a scraping mechanism is installed at the bottom of the inner cavity of the reactor, the scraping mechanism scrapes and removes flocs adsorbed by the adsorption carrier during movement that exceeds a rotational speed threshold, and dynamically controls the rotational speed by monitoring the distribution of flocs in the reaction liquid, thereby maximizing the reaction efficiency while maintaining the floc content in the reaction liquid within a normal range.

[0006] Preferably, the contraction-expansion mixing assembly includes a main shaft, both ends of which are rotatably mounted between the left and right side walls of the inner cavity of the reactor and connected to the power end in the power base, and both ends of the main shaft are fixedly mounted with mounting parts, each of the mounting parts is evenly distributed and mounted with a number of elastic spiral mixing plates, and the adsorption carrier is connected between two adjacent elastic spiral mixing plates on the left and right sides respectively.

[0007] Preferably, a connecting ring is fixedly connected to the end face of the elastic spiral mixing plate close to the center line direction of the power base, and the connecting ring is slidably installed on the adsorption carrier component, and end caps are fixedly installed at both ends of the adsorption carrier component.

[0008] Preferably, the adsorption protrusions are equidistantly distributed on the adsorption carrier, and an empty groove is formed between the adsorption protrusions of two adjacent adsorption carriers in the length direction. Slide portions are equidistantly distributed on the inner ring end face of the connecting ring, and each slide portion slides and abuts against the corresponding empty groove. During the change of the speed, the movement of the connecting ring can drive the slide portion to remove the flocs remaining on the adsorption carrier.

[0009] Preferably, the scraping mechanism includes a connecting plate portion, and two floats are rotatably installed between the two connecting plate portions. The outer end of the float located on the upper side is connected to an elastic interwoven mesh layer, and the outer end of the float located on the lower side is connected to a nylon brush surface layer. A first round rod and a second round rod are fixedly connected to the connecting plate portion. The first round rod passes through the inner side surface of the elastic interwoven mesh layer to support the elastic interwoven mesh layer at the bottom to form a bulge, and the second round rod passes through the inner side surface of the nylon brush surface layer to support the nylon brush surface layer at the top to form a bulge, and the two bulges abut each other.

[0010] Preferably, a plurality of grooves are evenly spaced at the bottom of the first round rod, and a plurality of raised teeth are evenly spaced at the top of the second round rod. The raised teeth can be embedded in the corresponding grooves to achieve mutual engagement of the elastic interwoven mesh layer and the nylon brush surface layer at the raised portions.

[0011] Preferably, a discharge platform is fixedly provided at the bottom of the inner cavity of the reactor, and a discharge cavity is provided at the bottom discharge port of the discharge platform. Limiting grooves are respectively provided on the left and right side walls of the discharge cavity, and a floating platform cover is respectively installed on each of the connecting plate parts, and the floating platform cover is slidably installed in the corresponding limiting groove.

[0012] Preferably, the adsorption carrier is configured as an iron rod with a rough surface.

[0013] Preferably, the adsorption protrusions are made of aluminum sulfate with a slow-release coating on the surface.

[0014] Preferably, a sensor module is installed on the side wall of the inner cavity of the reactor, and the sensor module monitors the floc content in the reaction solution in real time. When the floc content exceeds a set threshold, the rotation speed is increased until the carrier abuts against the elastic interwoven mesh layer, thereby removing the flocs in the upper reaction solution.

[0015] In summary, the beneficial effects of the present invention are:

[0016] The present invention dynamically controls the mixing speed by real-time monitoring of the floc content in the reaction solution. Once the floc content in the reaction solution exceeds the standard, the speed is promptly increased to utilize the adsorption carrier to adsorb the flocs and bring them to the discharge chamber at the bottom, thereby ensuring that the floc content in the upper layer of the reaction solution is always within a normal range and does not affect the main reaction. The problem of flocs wrapping reactants is effectively avoided, and the excess flocs are promptly removed to maintain the activity of the reaction interface and simultaneously maintain the maximum reaction rate for removing fluoride ions. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 This is a schematic diagram of the main structure of a fluorine-containing wastewater purification system of the present invention;

[0019] Figure 2 This is a schematic diagram of the main cross-sectional structure of a fluorine-containing wastewater purification system of the present invention;

[0020] Figure 3 This is a schematic structural diagram of a mixing mechanism in a fluorine-containing wastewater purification system of the present invention;

[0021] Figure 4 This is a schematic structural diagram of a mixing mechanism in a fluorine-containing wastewater purification system of the present invention;

[0022] Figure 5 This is a schematic top view of the structure of a mixing mechanism in a fluorine-containing wastewater purification system of the present invention;

[0023] Figure 6 This is a schematic structural diagram of an adsorption carrier in a fluorine-containing wastewater purification system of the present invention;

[0024] Figure 7 This is a schematic structural diagram of a connecting ring in a fluorine-containing wastewater purification system of the present invention;

[0025] Figure 8This is a schematic structural diagram of an elastic spiral mixing plate in a fluorine-containing wastewater purification system of the present invention;

[0026] Figure 9 This is a structural schematic diagram of a scraping mechanism in a fluorine-containing wastewater purification system of the present invention;

[0027] Figure 10 This is a structural schematic diagram of a connecting plate portion in a fluorine-containing wastewater purification system of the present invention;

[0028] Figure 11 This is a schematic structural diagram of a first round rod and a second round rod in a fluorine-containing wastewater purification system of the present invention;

[0029] Figure 12 This is a partially enlarged structural schematic diagram of the first round rod and the second round rod in a purification system for fluorine-containing wastewater of the present invention.

[0030] The symbols in the accompanying drawings are described as follows: power base 10; control panel 11; connecting part 12; reactor 13; second feeding port 14; first feeding port 15; discharge platform 17; limiting groove 18; discharge chamber 19; mixing mechanism 20; main shaft 21; mounting part 22; elastic spiral mixing plate 23; adsorption carrier part 24; end cover part 25; connecting ring 26; adsorption protrusion 27; slide part 28; scraping mechanism 30; floating platform cover 31; connecting plate part 32; float 33; elastic interwoven mesh layer 34; nylon brush surface layer 35; first round rod 36; second round rod 37; raised tooth part 38; groove mouth 39; sensor module 40. DETAILED DESCRIPTION

[0031] The present invention will now be further described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work are within the scope of protection of the present invention. These drawings are all simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic way, and therefore only show the structures related to the present invention.

[0032] To facilitate understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. Several embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0033] All features disclosed in this specification, or all steps in the disclosed methods or processes, except mutually exclusive features and / or steps, can be combined in any manner.

[0034] Any feature disclosed in this specification (including any appended claims, abstract, and drawings), unless otherwise stated, may be replaced by other equivalent or similar features. In other words, unless otherwise stated, each feature is only an example of a series of equivalent or similar features.

[0035] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connected," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; they can refer to mechanical connection, direct connection, or indirect connection through an intermediate medium; they can refer to internal communication between at least two elements or interaction between at least two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0036] The following combination Figures 1-12 The present invention is described in detail. For the convenience of description, the directions mentioned below are defined as follows: the up, down, left, right, front and back directions mentioned below are the same as Figure 2 The front, back, left, right, up and down directions of the view are consistent. Figure 2 It is a front view of the device of the present invention, Figure 2 The directions shown are consistent with the front, back, left, right, up and down directions of the device of the present invention when viewed from the front.

[0037] See also Figures 1-12 The present invention provides an embodiment: In the process of purifying fluoride-containing wastewater, multiple process stages are often required, including a pretreatment stage: adjusting water quality and pH, adding calcium salt for chemical precipitation for primary treatment, adding aluminum salt and iron salt for secondary treatment, and deep treatment for adsorption. The more important one is the primary treatment after pretreatment, which requires the addition of calcium salt to generate calcium fluoride precipitation. This part is relatively low in cost. If most of the fluoride can be removed in the primary treatment, it will be of great help to the subsequent processes and can greatly reduce the cost of wastewater purification. However, it is found that the calcium fluoride particles generated in the process of adding calcium salt for chemical precipitation are small, and the flocs are loose and difficult to settle quickly. Excessive flocs will in turn inhibit the formation of calcium fluoride. The flocs may wrap unreacted calcium salt particles or fluoride ions, hindering the full progress of the reaction and resulting in reduced calcium salt utilization. Excessive addition of reagents will further increase costs and reduce the fluoride ion removal effect. Therefore, a solution is provided to address this phenomenon.

[0038] In a purification system for fluorine-containing wastewater, it specifically includes a power base 10, a reactor 13, a mixing mechanism 20 and a scraping mechanism 30. The reactor 13 is installed between the columns at both ends of the power base 10, and the power output source is set in the column on the right. At the same time, a control panel 11 is set on the column on the right for control. The reaction solution needs to be added from the first feeding port 15, and the chemical reagents such as calcium salt for precipitation are added from the second feeding port 14. The mixing mechanism 20 is installed in the inner cavity of the reactor 13. The mixing mechanism 20 includes a contraction and expansion type mixing component and an adsorption carrier 24. The contraction and expansion type mixing component can adaptively expand within a range according to the rotation speed to fully mix the reaction liquid, and at the same time cooperate with the adsorption carrier 24 to promote stirring while using the adsorption protrusions 27 distributed on the adsorption carrier 24 to adsorb the flocs produced by the reaction. A scraping mechanism 30 is installed at the bottom of the inner cavity. Once the speed of the contraction-expansion mixing component is controlled to exceed the set speed threshold during the mixing process, the adsorption carrier 24 will expand outward and rotate due to centrifugal action. At this time, the scraping mechanism 30 scrapes and moves the flocs adsorbed on the adsorption carrier 24 to the discharge cavity 19 at the bottom to avoid the floc content in the upper reaction solution. The sensor module 40 installed on the side wall of the inner cavity of the power base 10 is used to monitor the flocs in the reaction solution, dynamically adjust the speed, maximize the reaction efficiency, and maintain the floc content in the reaction solution within a normal range. During the reaction process of precipitating fluoride ions using calcium salt, the condition of the flocs in the reaction solution is monitored at all times. Once the floc content is too high, the speed is controlled to use the adsorption carrier 24 to adsorb and remove the flocs, thereby avoiding the flocs affecting the precipitation of fluoride ions and accelerating the reaction efficiency.

[0039] refer to Figure 6 In addition, in one embodiment, the adsorption carrier 24 must first have certain mechanical properties to stir the reaction solution, and the surface is roughened to improve the ability to intercept flocs, while the adsorption protrusion 27 has certain adsorption properties to guide the adsorption of flocs. Here, the adsorption carrier 24 is set to be an iron rod with a rough surface, and the adsorption protrusion 27 is made of aluminum sulfate with a slow-release coating on the surface;

[0040] Aluminum sulfate is hydrolyzed in water to generate positively charged Al(OH)3 colloid, which promotes the aggregation of suspended particles and colloidal substances into flocs through electrical neutralization and adsorption bridging. The aluminum sulfate attached to the surface of the iron rod can continuously release Al 3+ , a coagulation environment can be formed locally, directly promoting the formation of flocs, and at the same time forming a synergistic effect with the rough iron rod. The surface of the iron rod provides a rough porous structure, which can physically intercept the flocs and the Fe released by iron corrosion. 2+ / Fe 3+ Hydrolysis generates Fe(OH)2 or Fe(OH)3 colloids, which synergistically enhance flocculation with Al(OH)3. Iron and aluminum sulfate may form micro-batteries, change the local pH or redox potential, and optimize the coagulation conditions. The combined effect of the adsorption carrier 24 and the adsorption protrusion 27 is utilized, and aluminum sulfate provides coagulation. The iron rod enhances floc capture through adsorption and synergistic chemical effects.

[0041] refer to Figure 3 、 Figure 4 and Figure 8 It is worth mentioning that in this embodiment, the contraction and expansion type mixing assembly includes a main shaft 21, which is connected to the power output end of the right column of the power base 10, and the two ends of the main shaft 21 are respectively rotatably mounted between the left and right side walls of the inner cavity of the reactor 13, and the two ends of the main shaft 21 are respectively fixedly mounted with mounting parts 22, and five elastic spiral mixing plates 23 are evenly distributed on each of the mounting parts 22, and the adsorption carrier part 24 is respectively connected between the two adjacent elastic spiral mixing plates 23 on the left and right sides. Due to the characteristics of the elastic spiral mixing plate 23, the greater the speed during rotation, the greater the expansion of the end of the elastic spiral mixing plate 23 close to the center direction of the power base 10, just like a flower opening, so that the adsorption carrier part 24 will also expand outward during rotation, and when the speed becomes smaller, the elastic spiral mixing plate 23 will shrink to its original position, and the adsorption carrier part 24 will gradually move inward.

[0042] refer to Figure 6 and Figure 7 It should be noted that, in this embodiment, the end face of the elastic spiral mixing plate 23 close to the center line direction of the power base 10 is fixedly connected with a connecting ring 26, which is connected to the adsorption carrier part 24 by means of the connecting ring 26. At the same time, end cover parts 25 are provided at both ends of the adsorption carrier part 24 for limiting. When the elastic spiral mixing plate 23 contracts and expands, the connecting ring 26 will slide on the adsorption carrier part 24, and the adsorption protrusions 27 are equidistantly distributed on the adsorption carrier part 24. An empty groove is formed between the adsorption protrusions 27 of two adjacent adsorption carrier parts 24 in the length direction. Slide parts 28 are equidistantly distributed on the inner ring end face of the connecting ring 26. Each slide part 28 slides against the corresponding empty groove. During the speed change process, the movement of the connecting ring 26 can drive the slide part 28 to remove the flocs remaining on the adsorption carrier part 24.

[0043] refer to Figure 2 、 Figure 9 、 Figure 10 and Figure 11It is also worth mentioning that in this embodiment, the scraping mechanism 30 includes a connecting plate portion 32, a discharge platform 17 is fixedly provided at the bottom of the inner cavity of the reactor 13, and a discharge cavity 19 is provided at the bottom discharge port of the discharge platform 17. Limiting grooves 18 are respectively provided on the left and right side walls of the discharge cavity 19, and a floating platform cover 31 is respectively installed on each of the connecting plate portions 32. The floating platform cover 31 is slidably installed in the corresponding limiting groove 18, and two floats 33 are rotatably installed between the two connecting plate portions 32. The interior of the float 33 is hollow and has a large buoyancy in water, and the outer end of the float 33 on the upper side is connected to an elastic interwoven mesh layer 34, and the outer end of the float 33 on the lower side is connected to a nylon brush surface layer 35. The elastic interwoven mesh layer 34 is mainly in contact with the adsorption carrier 24 to remove the adsorption The flocs absorbed on the carrier member 24 are "snatched" over, and the nylon brush surface layer 35 peels off the flocs "snatched" from the elastic interwoven mesh layer 34. In order to peel off the flocs more fully, a first round rod 36 and a second round rod 37 are fixedly connected to the connecting plate portion 32. The first round rod 36 passes through the inner side surface of the elastic interwoven mesh layer 34 to support the elastic interwoven mesh layer 34 at the bottom to form a bulge, and the second round rod 37 passes through the inner side surface of the nylon brush surface layer 35 to support the nylon brush surface layer 35 at the top to form a bulge. The two bulges abut against each other, and the formed bulge can also be tightened, so that the nylon brush surface layer 35 will be more fully in contact with the elastic interwoven mesh layer 34. The nylon brush surface layer 35 peels off the flocs on the elastic interwoven mesh layer 34 and transfers them to the discharge cavity 19 as it rotates.

[0044] When the rotation speed is controlled to allow the elastic spiral mixing plate 23 to shrink to a suitable expansion range, the adsorption carrier 24 will abut against the outer surface of the elastic interwoven mesh layer 34 during the rotation. Since the float 33 itself has buoyancy, a certain amount of extrusion will be formed between the elastic interwoven mesh layer 34 and the adsorption carrier 24. The rotation of the adsorption carrier 24 will apply a tangential force to the elastic interwoven mesh layer 34 when it is in extrusion contact with the elastic interwoven mesh layer 34, thereby driving the elastic interwoven mesh layer 34 to rotate. Then, the elastic interwoven mesh layer 34 will peel off the flocs on the adsorption carrier 24 and rotate to the raised position below, thereby abutting against the nylon brush surface layer 35. Similarly, due to the friction force, the nylon brush surface layer 35 will rotate, and the flocs will migrate to the discharge chamber 19 at the bottom, thereby effectively reducing the floc content in the upper solution.

[0045] refer to Figure 12It should be noted that in order to further remove the flocs more thoroughly, in this embodiment, a plurality of grooves 39 are evenly distributed on the bottom of the first round rod 36, and a plurality of raised teeth 38 are evenly distributed on the top of the second round rod 37. The raised teeth 38 can be embedded in the corresponding grooves 39, so that the elastic interwoven mesh layer 34 and the nylon brush surface layer 35 can be engaged with each other at the protrusions. Once engaged, the friction between the nylon brush surface layer 35 and the elastic interwoven mesh layer 34 will be greater, thereby making the flocs more thoroughly removed.

[0046] Specific runtime

[0047] First, a preliminary test of the fluoride ion concentration in the wastewater to be treated was conducted, and the characteristics of the wastewater were obtained as follows: fluoride ion concentration: 200 mg / L and initial pH: 3.5. The corresponding target parameters were set according to the characteristics of the wastewater to be treated, among which the target turbidity was 15 NTU (corresponding to F - ≤50 mg / L), maximum allowable floc content: 100 mg / L (sensor module 40 threshold), speed threshold: 200 rpm (triggering scraping mechanism action);

[0048] The expansion range of the elastic spiral mixing plate 23 is positively correlated with the rotational speed. When the rotational speed is greater than 200 rpm, it will expand until the carrier 24 abuts against the elastic interwoven mesh layer 34, triggering the scraping mechanism to operate.

[0049] The aluminum sulfate slow-release coating on the iron rod surface (Al 3+ Release rate 0.5 mg / min·cm 2 );

[0050] The sensor module 40 monitors turbidity (0-500 NTU), floc content (mg / L), and pH (0-14) in real time;

[0051] Wastewater treatment is divided into three stages

[0052] The first stage is: initial dosing and rapid mixing stage (0-5 minutes);

[0053] Goal: Rapidly disperse calcium salt (CaCl2) to initiate calcium fluoride precipitation reaction;

[0054] In the first stage of mixing, the initial rotation speed is set to 250 rpm. At this time, the elastic spiral mixing plate 23 is fully unfolded, and the adsorption carrier 24 is expanded to the maximum position to fully stir and mix the reaction solution. When it is expanded to the maximum position, the adsorption carrier 24 will intermittently rotate to the top of the reaction solution page to contact with the air, which will promote the corrosion of iron and release Fe 3+, enhancing the synergistic effect of coagulation, when the iron rod is exposed to air, an oxidation reaction occurs on the surface (Fe → Fe 2+ →Fe 3+ ), releases Fe 3+ Hydrolysis generates Fe(OH)3 colloid, which forms a composite flocculant (Al-Fe copolymer) with Al(OH)3 colloid hydrolyzed by aluminum sulfate. The adsorption capacity and electrical neutralization effect of this composite colloid are stronger than those of single aluminum salt or iron salt, which can significantly improve the capture efficiency of calcium fluoride microcrystals. At the same time, when the adsorption carrier 24 comes into contact with the air due to high-speed stirring, the shearing effect draws the air into the liquid phase to form micron-sized bubbles (20-50μm). These bubbles can adhere to the surface of the hydrophobic flocs, reduce the density of the flocs, promote their floating to the liquid surface, reduce the residence time of the flocs in the reaction zone, and avoid wrapping unreacted Ca 2+ or F - ;

[0055] At the same time, the sensor provides real-time feedback: the turbidity increases from 5 NTU to 120 NTU (reaction start sign).

[0056] The second stage is: floc growth and dynamic speed regulation stage (5-25 minutes);

[0057] Objective: Balance floc growth and shear breakage, maintaining turbidity ≤15 NTU;

[0058] If the real-time turbidity is greater than 15 NTU, the rotation speed is reduced to 150 rpm (the elastic spiral mixing plate 23 is contracted), the shear force is reduced and the floc growth time is prolonged, the adsorption carrier 24 is retracted, and the contact area between the adsorption protrusion 27 and the floc is increased by 20%. If the real-time turbidity is less than or equal to 15 NTU, the rotation speed is maintained at 180 rpm to stabilize the Al 3+ Release rate;

[0059] When the floc content is monitored to be greater than 100 mg / L, the speed is instantly increased to 220 rpm (triggering the scraping mechanism 30), the adsorption carrier part 24 expands outward, and the carrier 24 is used to adsorb the flocs. At the same time, it contacts the elastic interwoven mesh layer 34, "snatches" the flocs on the carrier 24, and the nylon brush surface layer 35 peels off the flocs and transfers them to the discharge chamber 19 (removal efficiency ≥ 70%) to maintain the floc content in the upper reaction solution. After the floc content drops to a safe range, the speed is reduced again. The adsorption carrier part 24 exposes more adsorption sites during high-speed expansion, and cooperates with the scraping mechanism 30 to immediately remove overloaded flocs to avoid the wrapping effect.

[0060] The third stage is: stability maintenance and settlement preparation (25-30 minutes)

[0061] Goal: To protect mature flocs and prepare for sedimentation and separation;

[0062] At this time, the reaction is basically completed, the rotation speed drops to 80 rpm, the elastic spiral mixing plate 23 shrinks, and the adsorption carrier 24 moves closer to the main shaft 21.

[0063] Through the target turbidity-oriented speed adaptive control, combined with the adsorption-scraping dual-effect mechanism, the problem of calcium fluoride flocs being difficult to settle and encapsulate reactants in the primary treatment was successfully solved. The high-speed mixing period can maximize the reaction rate and generate initial floc nuclei; the dynamic adjustment period: balances shear force and floc integrity to avoid overload; the intelligent scraping period: instantly removes excess flocs and maintains the activity of the reaction interface. Actual operation data shows that the system can stably control the effluent F - ≤50 mg / L, saving more than 30% of the cost for subsequent secondary treatment (aluminum salt / adsorption), suitable for high-fluoride industrial wastewater scenarios.

[0064] The above description is merely a specific embodiment of the invention, but the scope of protection of the invention is not limited thereto. Any changes or substitutions that are not conceived through creative effort should be included within the scope of protection of the invention. Therefore, the scope of protection of the invention should be based on the scope of protection defined in the claims.

Claims

1. A fluorine-containing wastewater purification system, comprising a power base (10) and a reaction kettle (13), characterized in that: A mixing mechanism (20) is installed in the inner cavity of the reactor (13) for automatically adjusting the floc adsorption range in the reaction solution based on the rotation speed. The mixing mechanism (20) includes a contraction-expansion type mixing component and an adsorption carrier (24). The contraction-expansion type mixing component includes a main shaft (21). The two ends of the main shaft (21) are respectively rotatably installed between the left and right side walls of the inner cavity of the reactor (13) and are connected to the power end in the power base (10). The two ends of the main shaft (21) are respectively fixed with mounting parts (22). A plurality of elastic spiral mixing plates (23) are evenly distributed and installed on each mounting part (22). The adsorption carrier (24) is respectively connected between two adjacent elastic spiral mixing plates (23) on the left and right sides. During the rotation process, the speed increases. The larger the speed, the larger the end of the elastic spiral mixing plate (23) closer to the center of the power base (10) will spread. The adsorption carrier (24) will also expand outward during the rotation process. When the speed becomes smaller, the elastic spiral mixing plate (23) will shrink to its original position. At the same time, the adsorption carrier (24) will gradually move inward. The outer surface of the adsorption carrier (24) is distributed with a plurality of adsorption protrusions (27). The bottom of the inner cavity of the reactor (13) is equipped with a scraping mechanism (30). The scraping mechanism (30) scrapes and moves the flocs adsorbed by the adsorption carrier (24) during the movement exceeding the speed threshold. The speed is dynamically controlled by monitoring the distribution of flocs in the reaction liquid, maximizing the reaction efficiency while maintaining the floc content in the reaction liquid within a normal range.

2. A fluorine-containing wastewater purification system according to claim 1, characterized in that: A connecting ring (26) is fixedly connected to the end surface of the elastic spiral mixing plate (23) close to the center line direction of the power base (10), and the connecting ring (26) is slidably mounted on the adsorption carrier (24). End caps (25) are respectively fixedly mounted on both ends of the adsorption carrier (24).

3. A fluorine-containing wastewater purification system according to claim 2, characterized in that: The adsorption protrusions (27) are equidistantly distributed on the adsorption carrier (24), and an empty groove is formed between the adsorption protrusions (27) of two adjacent adsorption carriers (24) in the length direction. Slides (28) are equidistantly distributed on the inner ring end surface of the connecting ring (26), and each slide (28) slides and abuts against the corresponding empty groove. During the change of the rotation speed, the movement of the connecting ring (26) can drive the slide (28) to remove the flocs remaining on the adsorption carrier (24).

4. A fluorine-containing wastewater purification system according to claim 3, characterized in that: The scraping mechanism (30) includes a connecting plate portion (32), and two floats (33) are rotatably installed between the two connecting plate portions (32). The outer end of the float (33) located on the upper side is connected to an elastic interwoven mesh layer (34), and the outer end of the float (33) located on the lower side is connected to a nylon brush surface layer (35). A first round rod (36) and a second round rod (37) are fixedly connected to the connecting plate portion (32). The first round rod (36) passes through the inner side surface of the elastic interwoven mesh layer (34) to support the elastic interwoven mesh layer (34) at the bottom to form a bulge. The second round rod (37) passes through the inner side surface of the nylon brush surface layer (35) to support the nylon brush surface layer (35) at the top to form a bulge. The two bulges abut against each other.

5. A fluorine-containing wastewater purification system according to claim 4, characterized in that: The bottom of the first round rod (36) is provided with a plurality of groove openings (39) at equal intervals, and the top of the second round rod (37) is provided with a plurality of raised teeth (38) at equal intervals. The raised teeth (38) can be embedded in the corresponding groove openings (39), so that the elastic interwoven mesh layer (34) and the nylon brush surface layer (35) can be engaged with each other at the raised parts.

6. A fluorine-containing wastewater purification system according to claim 5, characterized in that: The adsorption carrier (24) is configured as an iron rod with a rough surface.

7. A fluorine-containing wastewater purification system according to claim 6, characterized in that: The adsorption protrusion (27) is made of aluminum sulfate with a slow-release coating on the surface.

8. A fluorine-containing wastewater purification system according to claim 7, characterized in that: A discharge platform (17) is fixedly provided at the bottom of the inner cavity of the reactor (13), and a discharge cavity (19) is provided at the bottom discharge port of the discharge platform (17). Limiting grooves (18) are respectively provided on the left and right side walls of the discharge cavity (19), and a floating platform cover (31) is respectively installed on each of the connecting plate parts (32), and the floating platform cover (31) is slidably installed in the corresponding limiting groove (18).

9. A fluorine-containing wastewater purification system according to claim 8, characterized in that: A sensor module (40) is installed on the inner cavity side wall of the reactor (13). The sensor module (40) monitors the floc content in the reaction solution in real time. When the floc content exceeds a set threshold, the rotation speed is increased until the adsorption carrier (24) abuts against the elastic interwoven mesh layer (34), thereby removing the flocs in the upper layer of the reaction solution.

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